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A comment on Shell Magic: Set Operations with uniq. Parent comment

Re:Shell Magic: Set Operations with uniq by TheDong on Tuesday May 29, 2018 @07:53PM (#17183770)
More accurately, it can be used for any command which expects a file and doesn't do anything too weird in reading it (e.g. doesn't seek to the beginning and read it again)

The '<( ... )' is just giving the path to that command's stdout as a file descriptor.

    $ ls <(echo hi)  
    /proc/self/fd/11
    $ vi <(echo hi)
    # opens vi with 'hi' as the contents
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Re:Shell Magic: Set Operations with uniq by therein on Wednesday May 30, 2018 @04:20AM (#17186007)
Thank you. I was just thinking of looking into how it was implemented.
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Re:Shell Magic: Set Operations with uniq by lloeki on Wednesday May 30, 2018 @08:28AM (#17187114)
It is called "process substitution", and can work the other way around:

http://www.tldp.org/LDP/abs/html/process-sub.html

With fish:

https://fishshell.com/docs/current/commands.html#psub

But there it only works one way:

https://github.com/fish-shell/fish-shell/issues/1786

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